The 22-day repair programme includes drainage improvements at Waterloo East and structural repairs to Hungerford Bridge.
“This section of track is more than 35 years old and has caused thousands of minutes of delays for passengers in recent years,” said Brightwell.
“By replacing it now, and combining that with platform, drainage and bridge works, we’re tackling the root causes of disruption in one go.
“This means fewer closures in the future.”
He added the team had explored options for carrying out the work and, while all had some impact, a single summer closure would be the least disruptive and most efficient.
Tickets will be accepted on alternative rail routes, as well as on the Tube and buses.